Chapter 38: Low back pain

Low back pain accounts for at least 5% of general practice presentations. It is a massive problem worldwide. The most common cause is minor soft tissue injury, but patients with this do not usually seek medical help because the problem settles within a few days.

Most back pain in patients presenting to GPs is postulated to be due to dysfunction of elements of the mobile segment, namely the facet joint, the intervertebral joint (with its disc) and the ligamentous and muscular attachments. This problem, often referred to as mechanical back pain, will be described as vertebral dysfunction—a general term that, while covering radicular and non-radicular pain, includes dysfunction of the joints of the spine, although the specific origin in most instances cannot be determined. It is therefore appropriate to refer to this as ‘non-specific back pain’.¹

To develop a comprehensive diagnostic approach, the practitioner should have a clear understanding of the possible causes of low back and leg pain and of the relative frequency of their clinical presentations. The major causes of low back pain in several hundred patients presenting to the author’s general practice are summarised in TABLE 38.1.

Relevant causes are illustrated in FIGURE 38.1.

Recent studies have focused on the importance of disruption of the intervertebral disc in the cause of back pain. A very plausible theory has been advanced by Maigne³ who proposes the existence, in the involved mobile segment, of a minor intervertebral derangement (MID). He defines it as ‘isolated pain in one intervertebral segment, of a mild character, and due to minor mechanical cause’.

The MID always involves one of the two apophyseal joints in the mobile segment, thus initiating nociceptive activity in the posterior primary dermatome and myotome.

Maigne points out that the functional ability of the mobile segment depends intimately upon the condition of the intervertebral disc. Thus, if the disc is injured, other elements of the segment will be affected. Even a minimal disc lesion can produce apophyseal joint dysfunction, which is a reflex cause of protective muscle spasm and pain in the corresponding segment, with loss of function (see FIG. 38.2).

In theory, any structure with a nociceptive nerve supply may be a source of pain. Such structures include the ligaments, fascia and muscles of the lumbosacral spine, intervertebral joints, facet joints, dura mater and sacroiliac joints.⁵

Actually, pain can theoretically arise from any innervated structure in the region of the spine. It can be neurogenic, spondylogenic, viscerogenic, vasculogenic or rarely psychogenic.

A summary of the diagnostic strategy model is presented in TABLE 38.2.

Probability diagnosis

The commonest cause of low back pain is vertebral dysfunction or mechanical pain, which then has to be further analysed. The term can embrace musculoskeletal strain, discogenic and posterior ligament pain, and facetogenic dysfunction/pain.

Degenerative changes in the lumbar spine (lumbar spondylosis) are commonly found in the older age group. This problem, and one of its complications, spinal canal stenosis, is steadily increasing along with the ageing population.

Serious disorders not to be missed

It is important to consider malignant disease, especially in an older person. It is also essential to consider infection such as acute osteomyelitis and tuberculosis, which is often encountered in recent immigrants, especially those from Asia and central Africa. The uncommon epidural or subdural abscess should also be kept in mind, especially if any fever (see CHAPTER 30). These conditions are considered in more detail under infections of the central nervous system. For pain or anaesthesia of sudden onset, especially when accompanied by neurological changes in the legs, consider cauda equina compression due to a massive disc prolapse and also retroperitoneal haemorrhage. It is important to ask patients if they are taking anticoagulants. See TABLE 38.3.

Pitfalls

The inflammatory disorders must be kept in mind, especially the spondyloarthropathies, which include psoriatic arthropathy, ankylosing spondylitis, reactive arthritis, inflammatory bowel disorders such as ulcerative colitis and Crohn disease, and reactive arthritis. The spondyloarthropathies are more common than appreciated and must be considered in the younger person presenting with features of inflammatory back pain (i.e. pain at rest, relieved by activity). The old trap of confusing claudication in the buttocks and legs, due to a high arterial obstruction, with sciatica must be avoided.

General pitfalls

• Being unaware of the characteristic symptoms of inflammation and thus misdiagnosing one of the spondyloarthropathies.

• Overlooking the early development of malignant disease or osteomyelitis; if suspected, and an X-ray is normal, a radionuclide scan should detect the problem.

• Failing to realise that mechanical dysfunction and osteoarthritis can develop simultaneously, producing a combined pattern.

• Overlooking anticoagulants as a cause of a severe bleed around the nerve roots and corticosteroids leading to osteoporosis.

• Not recognising back pain as a presenting feature of the drug addict.

Seven masquerades checklist

Of these conditions, depression and urinary tract infection have to be seriously considered. For the young woman with upper lumbar pain, especially if she is pregnant, the possibility of a urinary tract infection must be considered. These patients may not have urinary symptoms, such as dysuria and frequency.

Depressive illness has to be considered in any patient with a chronic pain complaint. This common psychiatric disorder can continue to aggravate or maintain the pain even though the provoking problem has disappeared.

This is more likely to occur in people who have become anxious about their problem or who are under excessive stress. Many doctors treat such patients with a therapeutic trial of antidepressant medication, for example, amitriptyline or doxepin.

Psychogenic considerations

The patient may be unduly stressed, not coping with life or malingering. It may be necessary to probe beneath the surface of the presenting problem.

A patient with low back pain following lifting at work poses a problem that causes considerable anguish to doctors, especially when the pain becomes chronic and complex. Chronic pain may be the last straw for patients who have been struggling to cope with personal problems; their fragile equilibrium is upset by the back pain. Many patients who have been dismissed as malingerers turn out to have a genuine problem. The importance of a caring, competent practitioner with an insight into all facets of his or her patient’s suffering, organic and functional, becomes obvious. The tests for non-organic back pain are very useful in this context.

The nature of the pain may reveal its likely origin. Establish where the pain is worst—whether it is central (proximal) or peripheral. The following are general characteristics and guides to diagnosis:

• aching throbbing pain = inflammation (e.g. sacroiliitis)

• deep aching diffuse pain = referred pain (e.g. dysmenorrhoea)

• superficial steady diffuse pain = local pain (e.g. muscular strain)

• boring deep pain = bone disease (e.g. neoplasia, Paget disease)

• intense sharp or stabbing (superimposed on a dull ache) = radicular pain (e.g. sciatica)

A comparison of the significant features of the two most common types of pain—mechanical and inflammatory—is presented in TABLE 38.4.

History

Analysing the history invariably guides the clinician to the diagnosis. The pain patterns have to be carefully evaluated and it is helpful to map the diurnal variations of pain to facilitate the diagnosis (see FIG. 38.3).

It is especially important to note the intensity of the pain and its relation to rest and activity. In particular, ask whether the pain is present during the night, whether it wakes the patient, is present on rising or whether it is associated with stiffness.

Continuous pain, present day and night, is suggestive of neoplasia or infection. Pain on waking also suggests inflammation or depressive illness. Pain provoked by activity and relieved by rest suggests mechanical dysfunction while pain worse at rest and relieved by moderate activity is typical of inflammation. In some patients the coexistence of mechanical and inflammatory causes complicates the pattern.

Pain aggravated by standing or walking that is relieved by sitting is suggestive of spondylolisthesis. Pain aggravated by sitting (usually) and improved with standing indicates a discogenic problem.

Pain of the calf that travels proximally with walking indicates vascular claudication; pain in the buttock that descends with walking indicates neurogenic claudication. This latter problem is encountered more frequently in older people who have a tendency to spinal canal stenosis associated with spondylosis.

Key questions

• What is your general health like?

• Can you describe the nature of your back pain?

• Was your pain brought on by an injury?

• Is it worse when you wake in the morning or later in the day?

• How do you sleep during the night?

• What effect does rest have on the pain?

• What effect does activity have on the pain?

• Is the pain worse when sitting or standing?

• What effect does coughing or sneezing or straining at the toilet have?

• What happens to the pain in your back or leg if you go for a long walk?

• Do you have a history of psoriasis, diarrhoea, penile discharge, eye trouble or severe pain in your joints?

• Do you have any urinary symptoms?

• What medication are you taking? Are you on anticoagulants?

• Are you under any extra stress at work or home?

• Do you feel tense or depressed or irritable?

Examination

Physical examination

The basic objectives of the physical examination are to reproduce the patient’s symptoms, detect the level of the lesion and determine the cause (if possible) by provocation of the affected joints or tissues. This is done using the time-honoured method of joint examination— look, feel, move and test function. The patient should be stripped to a minimum of clothing so that careful examination of the back can be made. A neurological examination of the lower limb should be performed if symptoms extend below the buttocks. It is important to perform a rectal examination to check for flaccidity in a patient with suspected cauda equina syndrome.

A useful screening test for a disc lesion and dural tethering is the slump test.⁷

The main components of the physical examination are:

1. inspection

2. active movements:

   • forward flexion (to reproduce the patient’s symptoms)

   • extension (to reproduce the patient’s symptoms)

   • lateral flexion (R & L) (to reproduce the patient’s symptoms)

3. provocative tests (to reproduce the patient’s symptoms)

4. palpation (to detect level of pain)

5. neurological testing of lower limbs (if appropriate)

6. testing of related joints (hip, sacroiliac)

7. assessment of pelvis and lower limbs for any deformity (e.g. leg shortening)

8. general medical examination, including rectal examination

Important landmarks

The surface anatomy of the lumbar region is the basis for determining the vertebral level. Key anatomical landmarks include the iliac crest, spinous processes, the sacrum and the posterior superior iliac spines (PSISs).

• The tops of the iliac crest lie at the level of the L3–4 interspace (or the L4 spinous process).

• The PSISs lie opposite S2.

Inspection

Inspection begins from the moment the patient is sighted in the waiting room. A patient who is noted to be standing is likely to have a significant disc lesion. Considerable information can be obtained from the manner in which the patient arises from a chair, moves to the consulting room, removes the shoes and clothes, gets onto the examination couch and moves when unaware of being watched.

The spine must be adequately exposed and inspected in good light. Patients should undress to their underpants; women may retain their brassiere and it is proper to provide them with a gown that opens down the back. Note the general contour and symmetry of the back and legs, including the buttock folds, and look for muscle wasting. Note the lumbar lordosis and any abnormalities, such as lateral deviation. If lateral deviation (scoliosis) is present it is usually away from the painful side.

Note the presence of midline moles, tufts of hair or haemangioma that might indicate an underlying congenital anomaly, such as spina bifida occulta.

Movements of the lumbar spine

There are three main movements of the lumbar spine. As there is minimal rotation, which mainly occurs at the thoracic spine, rotation is not so important. The movements that should be tested, and their normal ranges, are as follows:

• extension (20–30°) (see FIG. 38.4a)

• lateral flexion, left and right (30°) (see FIG. 38.4b)

• flexion (75–90°: average 80°) (see FIG. 38.4a)

Measurement of the angle of movement can be made by using a line drawn between the sacrum and large prominence of the C7 spinous process.

Palpation

Have the patient relaxed, lying prone, with the head to one side and the arms by the sides. The levels of the spinous processes are identified by standing behind the patient and using your hands to identify the L4 and L5 spinous processes in relation to the top of the iliac crests. Mark the important reference points.

Palpation, which is performed with the tips of the thumbs opposed, can commence at the spinous process of L1 and then systematically proceed distally to L5 and then over the sacrum and coccyx. Include the interspinous spaces as well as the spinous processes. When the thumbs (or other part of the hand such as the pisiforms) are applied to the spinous processes, a firm pressure is transmitted to the vertebrae by a rocking movement for three or four ‘springs’. Significant reproduction of pain is noted.

Palpation occurs at three main sites:

• centrally (spinous processes to coccyx)

• unilateral—right and left sides (1.5 cm from midline)

• transverse pressure to the sides of the spinous processes (R and L)

Straight leg raising (SLR) test (Lasègue test)

This test is a passive test by the practitioner. The patient lies supine with both knees extended and the ankle dorsiflexed. The affected leg is raised slowly, keeping the knee extended. If sciatica with dural irritation is present, 20° to 60° of elevation causes reproduction of pain.

Slump test

The slump test is an excellent provocation test for lumbosacral pain and is more sensitive than the SLR test. It is a screening test for a disc lesion and dural tethering. It should be performed on patients who have low back pain with pain extending into the leg, and especially for posterior thigh pain.

A positive result is reproduction of the patient’s pain, and may appear at an early stage of the test (when it is ceased).

Method:

1. The patient sits on the couch in a relaxed manner with knees at the edge of the table.

2. The patient then slumps forward (without excessive trunk flexion), and then places the chin on the chest.

3. The unaffected leg is straightened.

4. The affected leg only is then straightened (see FIG. 38.5).

5. Both legs are straightened together.

6. The foot of the affected straightened leg is dorsiflexed.

Note: Take care to distinguish from hamstring pain. Deflexing the neck relieves the pain of spinal origin, not hamstring pain.

Significance of the slump test

• It is positive if the back or leg pain is reproduced.

• If positive, it suggests disc disruption.

• If negative, it may indicate lack of serious disc pathology.

• If positive, one should approach manual therapy with caution.

Neurological examination⁷

A neurological examination is performed only when the patient’s symptoms, such as pain, paraesthesia, anaesthesia and weakness, extend into the leg.

The importance of the neurological examination is to ensure that there is no compression of the spinal nerves from a prolapsed disc or from a tumour. This is normally tested by examining those functions that the respective spinal nerves serve, namely skin sensation, muscle power and reflex activity.

The examination is not daunting but can be performed quickly and efficiently in 2 to 3 minutes by a methodical technique that improves with continued use. The neurological examination consists of:

1. quick tests: walking on heels (L5), walking on toes (S1)

2. dural stretch tests: slump test, straight leg raising

3. specific nerve root tests (L4, L5, S1): sensation, power, reflexes

Main nerve roots

Refer to FIGURE 38.6 and to TABLE 66.3.

L3:

• femoral stretch test (prone, flex knee, extend hip)

• motor—extension of knee

• sensation—anterior thigh

• reflex—knee jerk (L3, L4)

L4:

• motor—resisted inversion foot

• sensation—inner border of foot to great toe

• reflex—knee jerk

L5:

• motor: walking on heels, resisted extension great toe

• sensation—middle three toes (dorsum)

• reflex—nil

S1:

• motor: walking on toes, resisted eversion foot

• sensation—little toe, most of sole

• reflex—ankle jerk (S1, S2)

Other examination

The method of examining the sacroiliac and hip joints is outlined in CHAPTER 65.

Investigations

Investigations for back pain can be classified into three broad groups: front-line screening tests; specific disease investigations; and procedural and preprocedural tests.

Plain X-rays of the lumbar spine are not routinely recommended in acute non-specific low back pain (pain <6 weeks) in the absence of ‘red flags’ as they are of limited diagnostic value and no benefits in physical function are observed.¹

Screening tests

These are most important for the patient presenting with chronic back pain, especially in the presence of ‘red flags’, when serious disease such as malignancy, osteoporosis, infection or spondyloarthropathy must be excluded. The screening tests for chronic pain are:

• plain X-ray

• urine examination (office dipstick)

• FBE; ESR/CRP

• serum alkaline phosphatase

• PSA in males >50 years

Specific disease investigation

Such tests include:

• peripheral arterial studies

• HLA-B₂₇ antigen test for ankylosing spondylitis and reactive arthritis

• serum electrophoresis for multiple myeloma (paraprotein)

• PSA for possible prostate cancer

• Brucella agglutination test

• blood culture for pyogenic infection and bacterial endocarditis

• bone scanning to demonstrate inflammatory or neoplastic disease and infections (e.g. osteomyelitis) before changes are apparent on plain X-ray

• tuberculosis studies

• X-rays of shoulder and hip joint

• electromyographic (EMG) studies to screen leg pain and differentiate neurological diseases from nerve compression syndromes

• radioisotope scanning

• technetium pyrophosphate scan of SIJ for ankylosing spondylitis

• selective anaesthetic block of facet joint under image intensification

• selective anaesthetic block of medial branches of posterior primary rami and other nerve roots

Procedural and preprocedural diagnostic tests

These tests should be kept in reserve for red flag pointers to chronic disorders, especially mechanical disorders, that remain undiagnosed and unabated, and where surgical intervention is planned for a disc prolapse requiring removal.

Depending on availability and merit, such tests include:

• CT scan

• myelography or radiculography

• discography

• MRI

Summary of diagnostic guidelines for spinal pain

• Continuous pain (day and night) = neoplasia, especially malignancy or infection.

• The big primary malignancy is multiple myeloma.

• The big three metastases are from lung, breast and prostate.

• The other three metastases are from thyroid, kidney/adrenal and melanoma.

• Pain with standing/walking (relief with sitting) = spondylolisthesis.

• Pain (and stiffness) at rest, relief with activity = inflammation.

• In a young person with inflammation think of ankylosing spondylitis.

• Stiffness at rest, pain with or after activity, relief with rest = osteoarthritis.

• Pain provoked by activity, relief with rest = mechanical dysfunction.

• Pain in bed at early morning = inflammation, depression or malignancy/infection.

• Pain in periphery of limb = discogenic → radicular or vascular → claudication or spinal canal stenosis → claudication.

• Pain in calf (ascending) with walking = vascular claudication.

• Pain in buttock (descending) with walking = neurogenic claudication.

• One disc lesion = one nerve root (exception is L5–S1 disc).

• One nerve root = one disc (usually).

• Two or more nerve roots—consider neoplasm.

• The rule of thumb for the lumbar nerve root lesions is L3 from L2–3 disc, L4 from L3–4, L5 from L4–5 and S1 from L5–S1.

• A large disc protrusion can cause bladder symptoms, either incontinence or retention.

• A retroperitoneal bleed from anticoagulation therapy can give intense nerve root symptoms and signs.

The common mechanical disorders of the intervertebral joints can cause non-specific back pain in children, which must always be taken seriously. Like abdominal pain and leg pain, it can be related to psychogenic factors, so this possibility should be considered by diplomatically evaluating problems at home, at school or with sport. It is helpful to remember that tight hamstrings are associated with non-specific back discomfort with poor forward flexion.

Especially in children under the age of 10, it is very important to exclude organic disease. Infections such as osteomyelitis and tuberculosis are rare possibilities, and ‘discitis’ has to be considered. This painful condition can be idiopathic, but can also be caused by the spread of infection from a vertebral body. It has characteristic radiological changes.

Tumours causing back pain include the benign osteoid osteoma and the malignant osteogenic sarcoma. Osteoid osteoma is a very small tumour with a radiolucent nucleus that is sharply demarcated from the surrounding area of sclerotic bone. Although more common in the long bones of the leg, it can occur in the spine.

In older children and adolescents (in whom back pain is common) the organic causes of back pain are more likely to be inflammatory, congenital or from developmental anomalies and trauma.

A prolapsed intervertebral disc, which can occur in adolescents, can be very unusual in its presentation. There is often marked spasm, with a stiff spine and lateral deviation, which may be out of proportion to the relatively lower degree of pain.

Other important conditions to consider are Scheuermann disease (which largely affects thoracic spine) and early onset ankylosing spondylitis.

Spondylolisthesis can occur in older children, usually due to a slip of L5 or S1, because the articular facets are congenitally absent or because of a stress fracture in the pars interarticularis. It is necessary to request standing lateral and oblique X-rays.

Consider a lumbar stress fracture in the adolescent, which can be caused by activity involving rotation and extension of the spine such as cricket fast bowling. It has an insidious onset and requires a high index of suspicion.

Traumatic spinal dysfunction is still the most common cause of back pain in the elderly and may represent a recurrence of earlier dysfunction. It is amazing how commonly disc prolapse and facet joint injury can present in the aged. However, degenerative joint disease is very common and, if advanced, can present as spinal stenosis with claudication and nerve root irritation due to narrowed intervertebral foraminae.

Special problems to consider are malignant disease, degenerative spondylolisthesis, vertebral pathological fractures and occlusive vascular disease.

Mechanical disruption of the vertebral segment or segments is the foremost cause to consider, while the main serious clinical syndromes are secondary to disruption with or without prolapse of the intervertebral disc, usually L4–5 or L5–S1.

TABLE 38.5 presents the general clinical features and diagnosis in acute back pain (fractures excluded) following vertebral dysfunction: the symptoms and signs can occur singly or in combination.

Fortunately, syndromes A and B are extremely rare, but, if encountered, urgent referral to a surgeon is mandatory. Clinical features of the cauda equina syndrome are presented in FIGURE 38.7. Syndrome B can follow a bleed in patients taking anticoagulant therapy or be caused by a disc sequestration after inappropriate spinal manipulation.

Vertebral dysfunction with non-radicular pain (non-specific back pain)

This outstanding common cause of low back pain is considered to be due mainly to dysfunction of the pain-sensitive facet joint. The precise pathophysiology is difficult to pinpoint.

Typical profile⁸

Management^1,6,8

• Activity directed by degree of pain but normal activity encouraged from outset

• Reassure that it is rarely serious and usually settles in time

• Back education program

• Analgesics—paracetamol (as for thoracic back pain)

• Consider short-term oral NSAIDs (particularly if inflammatory pattern)

• Exercise program and swimming (as tolerated)— conflicting evidence re efficacy

• Physical therapy—mobilisation, manipulation (for persistent problems, but conflicting evidence) (see later in this chapter)

Current evidence for acute low back pain can be summarised as follows:^3,6,7

• beneficial—advice to stay active and reassurance, NSAIDs

• likely to be beneficial—analgesics, spinal mobilisation/manipulation and stretching (reduces period of morbidity)

• unknown—back exercises, trigger point injections, acupuncture

  For chronic low back pain (pain >12 weeks):

• beneficial—back exercises, multidisciplinary treatment program

• likely benefit—analgesics, NSAIDs, trigger point injections, spinal mobilisation/manipulation

Radiculopathy

Radicular pain, caused by nerve root compression from a disc protrusion (most common cause) or tumour or a narrowed intervertebral foramina, typically produces pain in the leg related to the dermatome and myotome innervated by that nerve root. Leg pain may occur alone without back pain and vary considerably in intensity.

The two nerve roots that account for most of these problems are L5 and S1 and the commonest disc lesion is L4–5, closely followed by L5–S1. A disc can be confined, extruded or sequestrated. Most settle with time (6–12 weeks). The management is outlined at the end of this chapter and under ‘Sciatica’ (see CHAPTER 66).

Spondylolisthesis

About 5% of the population have spondylolisthesis but not all are symptomatic. The pain is caused by extreme stretching of the interspinous ligaments or of the nerve roots. The onset of back pain in many of these patients is due to concurrent disc degeneration rather than a mechanical problem. The pain is typically aggravated by prolonged standing, walking and exercise. The physical examination is quite diagnostic.

• Physical examination (significant): stiff waddling gait, increased lumbar lordosis, flexed knee stance, tender prominent spinous process of ‘slipped’ vertebrae, limited flexion, hamstring tightness or spasm

• Diagnosis confirmation: lateral X-ray (standing) (see FIG. 38.8)

Management

This instability problem can be alleviated with relief of symptoms by getting patients to follow a strict flexion exercise program for at least 3 months. The objective is for patients to ‘splint’ their own spine by strengthening the abdominal and spinal muscles.

Extension of the spine should be avoided, especially hyperextension. Gravity traction might help. Recourse to lumbar corsets or surgery (for spinal fusion) should be resisted, although it is appropriate in a few severe intractable cases.

Lumbar spondylosis

Lumbar spondylosis, also known as degenerative osteoarthritis or osteoarthrosis, is a common problem of wear and tear that may follow vertebral dysfunction, especially after severe disc disruption and degeneration.

Stiffness of the low back is the main feature of lumbar spondylosis. Although most people live with and cope with the problem, progressive deterioration can occur, leading to subluxation of the facet joints. Subsequent narrowing of the spinal and intervertebral foramen leads to spinal canal stenosis (see FIG. 38.9).

Management

• Basic analgesics (depending on patient response and tolerance)

• NSAIDs (judicious use)

• Appropriate balance between light activity and rest

• Exercise program and hydrotherapy (if available)—physiotherapy supervision

• Regular mobilisation therapy may help

• Consider trials of electrotherapy, such as TENS and acupuncture

• Consider decompressive surgery for spinal canal stenosis (see CHAPTER 66)

The seronegative spondyloarthropathies are a group of disorders characterised by involvement of the sacroiliac joints with an ascending spondylitis and extraspinal manifestations, such as oligoarthritis and enthesopathies (see FIG. 38.10; refer to CHAPTER 35). The pain and stiffness that are the characteristic findings of spinal involvement are typical of inflammatory disease: namely, worse in the morning, may occur at night and improves rather than worsens with exercise.

The main disorders in this group are ankylosing spondylitis, psoriatic arthritis, reactive spondyloarthropathies and the inflammatory bowel diseases. Hence the importance of searching for a history of psoriasis, diarrhoea, urethral discharge, eye disorders and episodes of arthritis in other joints.

Treatment

The earlier the treatment the better the outlook for the patient; the prognosis is usually good (see earlier in chapter). Refer to consultant for shared care. The basic objectives of treatment are:

• prevention of spinal fusion in a poor position

• relief of pain and stiffness

• maintenance of optimum spinal mobility

It is important to identify malignant disease and other space-occupying lesions as early as possible because of the prognosis and the effect of a delayed diagnosis on treatment.

With respect to the neurological features, more than one nerve root may be involved and major neurological signs may be present without severe root pain. The neurological signs will be progressive.

If malignant disease is proved and myeloma is excluded, a search should be made for the six main primary malignancies that metastasise to the spine (see FIG. 38.11). If the bone is sclerotic consider prostatic secondaries, some breast secondaries or Paget disease.

Like headache, back pain is a symptom of an underlying functional, organic or psychological disorder. Pre-occupation with organic causation of symptoms may lead to serious errors in the assessment of patients with back pain. Any vulnerable aching area of the body is subject to aggravation by emotional factors.

Depressed patients are generally less demonstrative than patients with extreme anxiety and conversion disorders and malingerers, and it is easier to overlook the non-organic basis for their problem.

A trial of antidepressants for a minimum of 3 weeks is recommended and quite often a positive response with relief of backache eventuates.

Failure to consider psychological factors in the assessment of low back pain may lead to serious errors in diagnosis and management. Each instance of back pain poses a stimulating exercise in differential diagnosis. A comparison of organic and non-organic features is presented in TABLE 38.6.

Assessment of the pain demands a full understanding of the patient. One must be aware of his or her type of work, recreation, successes and failures; and one must relate this information to the degree of incapacity attributed to the back pain.

Patients with psychogenic back pain, especially the very anxious, tend to overemphasise their problem. They are usually demonstrative, the hands being used to point out various painful areas almost without prompting. There is diffuse tenderness even to the slightest touch and the physical disability is out of proportion to the alleged symptoms. The pain distribution is often atypical of any dermatome and the reflexes are almost always hyperactive. It must be remembered that patients with psychogenic back pain—for example, depression and conversion disorders—do certainly experience back pain and do not fall for the traps set for the malingerer.

General aspects of management^1,6

The aim of treatment is to reduce pain, maintain function and minimise disability and work absenteeism and importantly the risk of chronicity.

Advice to stay active. Evidence from randomised controlled trials confirms that, in people with acute low back pain, advice to stay active speeds symptomatic recovery, reduces chronic disability and results in less time off work compared with bed rest or usual care.⁶ Encourage the patient to stay at work or return early if possible. Keep moving despite discomfort.⁷

The caring knowledgeable therapist. Evidence supports the positive value of education and reassurance from a confident, supportive and knowledgeable therapist.

Relative rest. For acutely painful debilitating back problems, 2 days of strict rest lying on a firm surface is optimal treatment.⁹ Resting for longer than 3 days does not produce any significant healing, and patients should be encouraged to return to activities of daily living as soon as possible.

Patient education. Appropriate educational material leads to a clear insight into the causes and aggravation of the back disorder plus coping strategies. This can be a component of cognitive behaviour therapy (if considered appropriate)

Heat. Thermography (hot or cold) is beneficial. Heat in the form of heat bags, hot flannels and similar methods can be of benefit, especially in the first 2–4 weeks of acute low back pain. Evidence shows that heat is more effective than placebo for pain relief.⁶

Exercises. An early graduated exercise program as soon as the acute phase settles has been shown to promote healing and prevent relapses.¹⁰ All forms of exercise (extension, flexion and isometric) appear to be equally effective (see FIG. 38.12). Supervised swimming is an excellent activity for back disorders. Physiotherapist supervision is optimal.

Studies support the use of exercises for chronic back pain rather than acute pain.³

Pharmacological agents

Basic analgesics¹¹

Paracetamol is recommended as the first-line analgesic but evidence is not clear cut. Evidence indicates that short-term NSAIDs (used cautiously) may benefit individual patients where paracetamol is ineffective.

NSAIDs¹¹

These are second-line and particularly useful where there is clinical evidence of inflammation, especially with the spondyloarthropathies, severe spondylosis and in acute radicular pain, to counter irritation on the nerve root. NSAIDs have been shown to be more effective than placebo in acute back pain for pain relief and overall improvement. There is no evidence to distinguish different NSAIDs.³

Opioids^6,11

The role of opioids is limited because any pain-control benefits are outweighed by the potential risks. They are not recommended but may be considered when paracetamol and NSAIDs are not recommended or are unable to provide pain control.

Injection techniques

Trigger point injection

This may be effective for relatively isolated points using 5–8 mL of local anaesthetic. Studies indicate that it is likely to be more beneficial for chronic back pain.³

Chymopapain

This enzyme has been advocated for the treatment of acute nuclear herniation that is still intact. The indications are similar for surgical discectomy. However, studies show that although it is more effective than placebo, it is less effective than surgical discectomy.¹²

Facet joint injection

Corticosteroid injection under radio-image intensification is widely used in some clinics. The procedure is delicate and expertise is required. Best evidence to date does not support the use of these injections.

Epidural injections

Injections of local anaesthetic with or without corticosteroids are used for chronic pain, especially for nerve root pain. The author favours the caudal (trans-sacral) epidural injection for persistent sciatica using 15 mL of half-strength local anaesthetic only (e.g. 0.25% bupivacaine) (see FIG. 38.13).

Others favour the use of steroids and the lumbar epidural approach. The evidence regarding effectiveness is conflicting.⁵

Physical therapy

Active exercises are the best form of physical therapy (see FIG.38.12a, b).

Passive spinal stretching at the end range is a safe, effective method (see FIG. 38.14). Spinal mobilisation is a gentle, repetitive, rhythmic movement within the range of movement of the joint. It is safe and quite effective and a variation of stretching.

Spinal manipulation is a high-velocity thrust at the end range of the joint. It is generally more effective and produces a faster response, but requires accurate diagnosis and greater skill. It is more effective for uncomplicated dysfunctional low back pain (without radicular pain), especially acute pain (see FIG. 38.15).^3,6,13,14 However, the evidence from controlled trials is conflicting. Adverse effects are uncommon, but can be serious.

Other treatments

The following treatments have advocates for the management of back pain, although clear-cut evidence for the efficacy of these modalities is still lacking:

• hydrotherapy

• traction

• TENS

• therapeutic ultrasound

• facet joint injection

• posterior nerve root (medial branch) blocks with or without denervation (by cryotherapy or radiofrequency)

• percutaneous vertebroplasty (injection of bone cement into fractured vertebra of osteoporosis)

• deep friction massage (in conjunction with mobilisation and manipulation)

• acupuncture (evidence for short-term benefit)

• biofeedback

• gravitational methods (home therapy)

• lumbar supports

The management of ‘mechanical’ back pain depends on the cause. Since most of the problems are mechanical and there is a tendency to natural resolution, conservative management is quite appropriate. The rule is: ‘if patients with uncomplicated back pain receive no treatment, one-third will get better within 1 week and by 3 weeks almost all the rest of the other two-thirds are better’.^14,15 Practitioners should have a clear-cut management plan with a firm, precise, reassuring and conservative clinical approach.

The problems can be categorised into general conditions for which the summarised treatment protocols are outlined.

• Acute pain = pain less than 6 weeks

• Subacute pain = pain 6–12 weeks

• Chronic pain = pain greater than 12 weeks

Acute low back pain⁶

The common problem of low back pain caused by facet joint dysfunction and/or limited disc disruption usually responds well to the following treatment (see box). The typical patient is aged 20–55 years, is well and has no radiation of pain below the knee.^15,16

Most of these patients can expect to be relatively pain-free in 14 days and can return to work early (some may not miss work and this should be encouraged). The evidence concerning spinal manipulation is that it reduces the period of disability.

Sciatica with or without low back pain

Sciatica is a more complex and protracted problem to treat, but most cases will gradually settle within 12 weeks (refer to CHAPTER 66). Conservative management is usually recommended in the first 6–8 weeks.

Acute⁶

• Explanation and reassurance

• Back education program

• Resume normal activities as soon as possible

• Regular non-opioid analgesics with review as the patient mobilises

• NSAIDs for 10–14 days, then cease and review

• If severe pain unrelieved, add an opioid that works well for the patient, such as tapentadol SR 50 mg (o) bd as necessary, for short-term use¹⁷

• Walking and swimming

• Weekly or 2-weekly follow-up

• Consider: a course of corticosteroids for very severe pain,⁶ e.g. prednisolone 50 mg for 5 days, then 25 mg for 5 days, gradually tapering to 3 weeks in total.

  or

  30 mg daily mane for 3 weeks, tapering to 0 over next 2 weeks (efficacy not clearly established)

Chronic

• Reassurance that problem will subside (assuming no severe neurological defects)

• Consider epidural anaesthesia (if slow response)

• Consider amitriptyline 10–25 mg (o) nocte increasing to maximum 75–100 mg or duloxetine

Note: An important controlled prospective study comparing surgical and conservative treatment in patients with sciatica over 10 years showed that there was significant relief of sciatica in the surgical group for 1–2 years but not beyond that time. At 10 years, both groups had the same outcome, including neurological deficits.¹⁸

Sacroiliac dysfunction

See CHAPTER 66.

Chronic back pain

The basic management of the patient with uncomplicated chronic back pain should follow the following guidelines:

• back education program and ongoing support

• encouragement of normal activity

• exercise program

• mindfulness-based stress reduction (evidence based)

• analgesics (e.g. paracetamol 665 mg (o) 8-hourly)

• NSAIDs for 14–21 days (especially if inflammation, i.e. pain at rest—relieved by activity and poor response to non-pharmacological treatment) and review

• duloxetine or amitriptyline (second-line therapy)^1,7

• trial of mobilisation or manipulation (at least three treatments)—if no contraindications^12,13 (low-quality evidence)

• consider trigger point injection

• a multidisciplinary rehabilitation team approach is recommended/back schools

Patients should be informed that an ongoing back care program should give them an excellent outlook. Prevention includes:

• education about back care, including a good layperson’s reference

• golden rules to live by: how to lift, sit, bend, play sport and so on

• an exercise program: a tailor-made program for the patient

• posture and movement training, such as the Alexander technique¹⁹ or the Feldenkrais technique²⁰

Urgent referral

• Myelopathy, especially acute cauda equina compression syndrome

• Severe radiculopathy with progressive neurologic deficit

• Spinal fractures

Other referrals

• Recalcitrant spinal canal stenosis

• Neoplasia or infection

• Undiagnosed back pain

• Paget disease

• Continuing pain of 3 months’ duration without a clearly definable cause

Hand-out sheets from Murtagh’s Patient Education 7th edition:

• Backache

• Exercises for your lower back

• Sciatica

• Spondylosis